DUBAI, United Arab Emirates— The sultanate of Oman has announced it will join an Islamic military alliance led by Saudi Arabia.

Oman’s decision Thursday comes just over a year after Saudi Arabia announced the creation of the alliance.

Oman said it joined the coalition “within the context of the importance to achieve peace, security and stability in regions dominated by armed terrorist violence.”

The purpose of the coalition of over 30 countries still remains unclear a year after its founding. It appears aimed at showing Sunni-ruled Saudi Arabia’s importance to the region amid tensions with Shiite power Iran.

Oman, which acts as an intermediary between Iran and the West, is one of the few regional countries not to join the Saudi-led campaign against the Shiite Houthi rebels in Yemen.